Synthesis of Spirocyclic Pyrrolidine Compounds via Silver-Catalyzed Asymmetric [3 + 2] Cycloaddition Reaction of Imino Esters with α-Alkylidene Succinimides

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(2), P. 1249 - 1255

Published: Jan. 4, 2024

In this study, the AgOAc/ThioClickFerrophos (TCF) complex was used to successfully catalyze asymmetric [3 + 2] cycloaddition between glycine imino esters and CO2Me-appended α-alkylidene succinimides afford spiropyrrolidines in good yields with high diastereo- enantioselectivities (up 95% ee). The silver/TCF afforded endo-(2,5-cis) cycloadducts contrast previous exo′-(2,5-trans) selective reaction ylidene-2,3-dioxopyrrolidine. A wide variety of bearing electron-donating electron-withdrawing groups on phenyl heteroaryl substrates were utilized reaction. scope investigated, which revealed that substituents α-benzylidene derivatives had negligible effect product yield stereoselectivity, could be efficiently as dipolarophiles.

Language: Английский

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La(OTf)₃-Catalyzed [3+2] Cycloaddition Reactions for the Synthesis of Benzo[d]oxazoles/Benzofurans

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(6), P. 3809 - 3820

Published: Feb. 23, 2024

The La(OTf)3-catalyzed [3+2] cycloaddition reactions for the synthesis of benzo[d]oxazoles/benzofurans via quinones and 1,2-di-tert-butyl-3-(cyanimino)diaziridine (1,3-di-tert-butyl-2-cyanoguanidine)/vinyl azides have been explored. A series 5-hydroxybenzofuran-4-carboxylic acid derivatives 5-hydroxybenzo[d]oxazole-4-carboxylic were conveniently obtained with high yields good stereoselectivities, which could be used further transformations to valuable compounds.

Language: Английский

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Access to β-Alkylated γ-Functionalized Ketones via Conjugate Additions to Arylideneisoxazol-5-ones and Mo(CO)₆-Mediated Reductive Cascade Reactions

ACS Omega, Journal Year: 2022, Volume and Issue: 7(10), P. 8808 - 8818

Published: March 4, 2022

1,4-Conjugate addition of ((chloromethyl)sulfonyl)benzenes to arylideneisoxazol-5-ones, followed by one-pot, N-selective trapping in the presence electrophiles, was investigated. This strategy led synthesis new, stable N-protected isoxazol-5-ones good yields and high diastereolectivity. The study reactivity obtained products Mo(CO)6/H2O system allowed development a cascade reaction leading novel methyl ketones unchanged dr bearing an uncommon chloromethinearylsulfonyl end group.

Language: Английский

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Organocatalytic Asymmetric Inverse-Electron-Demand Diels–Alder Reaction between Alkylidene Pyrazolones and Allyl Ketones: Access to Tetrahydropyrano[2,3-c]pyrazoles

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(13), P. 9584 - 9593

Published: June 1, 2023

Herein we report a catalytic asymmetric inverse-electron-demand Diels–Alder reaction between alkylidene pyrazolones and allyl ketones. Allyl ketone gets activated by bifunctional thiourea catalyst acts as dienolate in this reaction. The trisubstituted tetrahydropyrano[2,3-c]pyrazoles were obtained moderate to good yields with high diastereo- enantioselectivities. Few applications, including decarbonylation reaction, have been demonstrated.

Language: Английский

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Dipolarophile‐Steered Formal Stereodivergent Synthesis of 2,5‐cis/trans‐Pyrrolidines Based on Asymmetric 1,3‐Dipolar Cycloaddition of Imino Lactones

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(66)

Published: Sept. 11, 2023

The stereodivergent asymmetric synthesis of 2,5-trans/cis pyrrolidines by 1,3-dipolar cycloaddition using two different types activated alkenes is described. When ylidene-isoxazolones were employed as dipolarophiles, the Ag/(S,Sp )-iPr-FcPHOX-catalyzed [3+2] imino lactones proceeded with 2,5-trans selectivity. Subsequent decarboxylation isoxazolone rings produced stereoretention. In reaction acyclic enones alkenes, Ag/(R,Sp )-ThioClickFerrophos complex-catalyzed afforded 2,5-cis substituted in high yields and enantioselectivities. Therefore, these methods can be considered a formal 2,5-cis/trans pyrrolidines.

Language: Английский

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β-Trifluoromethylated enones as trifluoromethylated synthons in asymmetric catalysis

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(21), P. 5519 - 5537

Published: Jan. 1, 2023

This minireview describes the applications of β-trifluoromethylated enones in diverse asymmetric catalytic transformations since 2008, and incorporates mechanistic aspects, involving key intermediates reaction pathways.

Language: Английский

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Assembly of isoxazol-5-one with 2-unsubstituted imidazole N-oxides and aldehydes

Organic & Biomolecular Chemistry, Journal Year: 2022, Volume and Issue: 21(3), P. 651 - 659

Published: Dec. 19, 2022

A new synthetic protocol has been developed to construct polyfunctional isoxazol-5-one derivatives with imidazole moiety. It is based on the Knoevenagel condensation of aldehydes and subsequent Michael addition N-oxides as part a tandem three-component process. This reaction proceeds smoothly in moderate-to-good yield under catalyst-free conditions.

Language: Английский

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Phosphine-Promoted Tandem Intermolecular Diels–Alder Reactions with Pentadienyl 4-Nitrobenzoate as a Diene Precursor

Organic Letters, Journal Year: 2023, Volume and Issue: 25(35), P. 6506 - 6510

Published: Aug. 25, 2023

A phosphine-promoted tandem Diels–Alder reaction using pentadienyl 4-nitrobenzoate (α-vinyl MBH adduct) as a diene precursor with 3-olefinic oxindoles or CF3-activated ketones dienophiles has been developed. The proceeds through the formation of phosphonium intermediate via SN2′′ addition, which acts both D–A and for exomethylene moiety. This method offers metal-free step-efficient approach synthesizing exomethylene-bearing spirooxindoles dihydropyrans, are privileged structures found in natural products.

Language: Английский

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Antioxidant and Antimicrobial Activities of Some New Synthesized Triazole, Thiazolone, and Thiazine Containing Fused Rings of Imidazopyridine

Iraqi Journal of Science, Journal Year: 2024, Volume and Issue: unknown, P. 2373 - 2384

Published: May 30, 2024

Several heterocyclic compounds bearing an imidazo(1,2a)pyridine moiety have been synthesized in this work, including triazole, thiazol, and thiazolone. This was done by condensation of 2-aminopyridine with 4-bromophencyl bromide or 4-phenylphencyl to produce 2-substituted phenyl 1 2. The Vilsmeier-Haak reaction used create the aldehyde group at position 3 ring (3 4). 4 thiosemicarbazide afforded thiosemicarbazone derivatives 5 6 66 70% yields, respectively. These (5 6) were then subjected three different cyclization reactions obtain 1,3-thiazolone (7 8), 1,2,4-triazole (9 10), 1,3-thiazole (11 12) derivatives. FT-IR spectroscopy confirm structure these derivatives, 1H NMR for some them. A few produced examined antimicrobial antioxidant activities

Language: Английский

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α-Carbonyl Rh-Carbenoid Initiated Cascade Assembly of Diazobarbiturates with Alkylidene Pyrazolones for Synthesis of Spirofuropyrimidines

Molecules, Journal Year: 2024, Volume and Issue: 29(13), P. 3178 - 3178

Published: July 3, 2024

Catalyzed by Rh2(esp)2 (10 mol%) and (±)-BINAP (20 in DCE at 80 °C, the cascade assembly between diazobarbiturates alkylidene pyrazolones proceeded readily produced spiro-furopyrimidines 38–96% chemical yields. The structure of prepared spirofuro-pyrimidines was firmly confirmed X-ray diffraction analysis.

Language: Английский

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